Why Is My Coffee Grinder Not Grinding? How to Clean Espresso, Pour-Over, and Single-Origin Coffee Grinders

Many friends who started out with manual grinders have bought electric grinders to grind their coffee beans, aiming to free their hands from the tedious grinding process. However, electric grinders differ from manual ones and require attention to many details during use. A single mistake can easily shorten the grinder's lifespan and significantly reduce grind quality.

Recently, many friends have asked FrontStreet Coffee various questions about grinders at our store, so today FrontStreet Coffee will share some details worth noting when using an electric grinder.

1. Pay Attention to "Purging" and "Cleaning"

Yes, FrontStreet Coffee is mentioning two kinds of cleaning here. Although both involve cleaning the grinder, their specific methods and functions are completely different. The first, purging, is performed when we use the grinder to grind beans. If you often visit coffee shops for pour-over coffee, you may have noticed that baristas typically pre-grind a few coffee beans before grinding the beans for brewing.

The purpose of this action is not to test the grind size but to perform a quick cleaning of the grinder's burrs. As we all know, no matter how high-quality the grinder is, it will experience retention, meaning the ground coffee powder will be slightly less than the beans put in. This is because some coffee powder gets trapped in the burrs or internal gaps during grinding and cannot exit. In addition, darker-roasted or more flavorful beans will leave their oils and aromas attached to the burrs.

Without cleaning, these aromas, oils, and powder impurities will mix into the next batch of ground coffee, directly affecting the coffee's flavor and cleanliness. Therefore, we need to run a small amount of coffee beans through before actual grinding to remove these substances and avoid impacting coffee quality. Generally, FrontStreet Coffee uses 1-2g, or 3-4 coffee beans, for purging: too little will not be effective, while too much would be wasteful. However, when we frequently grind dark-roasted beans, we need to perform regular deep cleaning of the grinder — this is the second kind of cleaning that FrontStreet Coffee mentioned.

Dark-roasted beans often carry more oils, and those oils cannot be completely removed simply by running coffee beans through. When oils remain in the burrs for too long, they can produce off-flavors through oxidation. Moreover, oils increase the grinder's retention, causing more powder to remain inside. Therefore, if you grind dark-roasted beans frequently, you should clean your grinder more frequently as well. As for how to clean it, FrontStreet Coffee has shared methods in previous articles that you can search for and learn about. Since grinder constructions are not universal, though, it is best to request the relevant cleaning tutorial from the manufacturer.

2. Start First, Add Beans Later

This is also an operation that FrontStreet Coffee often shares. When grinding coffee beans, it is best to start the grinder first and then add the beans. This approach offers two benefits: first, it reduces burr wear and the probability of jamming. When the grinder starts, the burrs go from stationary to stable rotation during a brief transition period, typically 0.5 to 1 second depending on the grinder's quality.

If we add beans first and then start the grinder, the presence of coffee beans increases the resistance when the burrs start, adding load to the motor. For some small household grinders, if the beans being ground are dense, this can easily cause jamming or failure due to motor overload. It also increases burr wear and shortens their lifespan. Although the wear may be minimal, it accumulates over time. Therefore, FrontStreet Coffee recommends starting the grinder first when grinding coffee beans, then adding the beans once the burrs are rotating stably. This effectively extends the life of the grinder and burrs and also improves the quality of the coffee powder thanks to consistent rotation speed.

3. Regularly Check the Grind Size

FrontStreet Coffee often recommends purchasing a #20 sieve to measure the sieve rate of coffee powder. This not only helps everyone use the same parameters and grind size for brewing coffee, but also allows you to calibrate the grinder's grind settings.

Have you noticed that as a grinder's usage time increases, the particles it produces become coarser, or that the brewed coffee becomes increasingly weaker and starts to show signs of under-extraction? This is the result of burr wear. Each time we grind coffee beans, we cause slight wear to the burrs. When wear accumulates, the burr spacing becomes wider, and the coffee powder ground at the same setting becomes coarser.

When the grind becomes coarser, coffee brewed with the same parameters naturally has less extracted material, so both the flavor and texture are less rich and full-bodied than at the beginning. Therefore, if you want to brew coffee with a rich flavor and full body again, you need to adjust the grind finer until it matches the original degree. Through a #20 sieve, we can directly find the corresponding grind setting. It is worth mentioning that this situation is most noticeable in espresso grinders: just looking at the scale indicator, you will see that the value has become much smaller than before.

4. Watch for Fine Powder Blockage

"Spinning without grinding" is a situation commonly found in espresso grinders. Simply put, when we start the grinder, the burrs are rotating but not grinding any coffee beans.

This is most likely caused by grinding too finely, which leaves coffee powder blocking the burrs. If you encounter this situation, the first step is to check whether fine powder blockage is the cause. If so, you can choose one of two solutions: the first is to adjust the grind coarser, increasing the spacing so grinding can resume; the second is to clean the grinder as mentioned earlier. Once the fine powder blocking the burrs is cleared, the grinder can resume its work.

The above are some small details to pay attention to when using an electric grinder. If you have additional tips, feel free to leave a comment.

FrontStreet Coffee Recommendation

Once your grinder is dialed in, the beans you feed it matter just as much. For light-roast pour-over, FrontStreet Yirgacheffe Gedingding is a classic starting point: it typically carries bright citrus, berry, and floral notes with a green-tea-like sweetness on the finish, and its acidity is soft and bright rather than sharp, which makes it very approachable for anyone new to pour-over. FrontStreet Ethiopia Huakui is the other star, with tropical fruit aromas of strawberry, passion fruit, jackfruit, and even lychee, plus obvious sweetness and very low bitterness.

For a more distinctive, juicy cup, FrontStreet Kenya Cherry Tomato is a Kenyan specialty washed bean from the Sicca region, grown at 1,550-1,750 meters from the classic SL28 and SL34 varieties. It uses a Kenyan 72-hour double washed fermentation, which draws out the fruit aromas while keeping the cup clean and pure; FrontStreet roasts it light to preserve the lively acidity and layered fruit. Expect clear cherry tomato and smoked plum, bright and solid acidity, a juicy mid-palate with pear and black plum, and a clean, long finish of yellow sugar and a hint of green tea.

If you prefer a heavier, low-acid profile, choose a medium-dark roast. FrontStreet PWN Indonesian Golden Mandheling is deep-roasted with very low acidity, a full and lingering body, and plenty of herbal and dark chocolate aroma with a faint earthy note. FrontStreet Brazil Queen's Estate is low in acidity and beautifully balanced, with intense nut and cocoa aromas, clear caramel sweetness, and a smooth, warming finish that works for pour-over, espresso, or moka pot. For a cup that balances acidity, sweetness, bitterness, and aroma, FrontStreet Jamaica Blue Mountain No. 1 is the benchmark, showing cream, caramel, chocolate, nuts, honey, and a light fruit note, smooth and rounded with a clean, long finish.